This proposal is based on the observation that b-catenin protein is localized to the leading edge of migrating astrocytes. In preliminary work we have examined this increase and determined it to be dependent upon new protein synthesis. Since cadherin/catenin signaling is known to be important in cell adhesion and migration we will attempt to characterize the molecular mechanism controlling the synthesis and localization of b-catenin protein in migrating astrocytes. In addition, b-catenin is a known oncogene and there is good evidence that the level of b-catenin protein is increased in some cancers. Close inspection of the mRNA encoding b-catenin has revealed a sequence that may regulate its translation. This sequence can be bound by the translational regulator CPEB1, and we have demonstrated that CPEB1 does indeed bind b-catenin mRNA. Further, we have identified the CPEB1-binding site in mRNA encoding other proteins known to play a role in glioblastoma pathology and we have shown that CPEB1 is highly active in a glioblastoma cell line. Based upon our preliminary data, we hypothesize that the mRNA-binding protein CPEB1 is regulating translation of mRNA encoding proteins mediating astrocyte and glioblastoma cell migration. To characterize CPEB1-mediated events in astrocytes, we will utilize a simple but elegant in vitro wound assay. Using astrocytes we will determine how CPEB1 regulates b-catenin expression at the leading edge of the cell. In addition, we will use reporter constructs that encode fluorescent protein and mRNA to track protein synthesis and mRNA localization respectively. Finally, we will use this knowledge to direct studies on glioblastoma cell migration that will attempt to inhibit CEPB1 function and determine the consequences on glioblastoma progression.